Re: [PATCH] gspca - ov534: Fix the light frequency filter

[Jean-Francois Moine <moinejf@free.fr>]

On Mon, 26 Nov 2012 14:08:06 +0100
Antonio Ospite <ospite@studenti.unina.it> wrote:

> For now I'd NAK the patch since it is a regression for users
> with 50Hz power sources and it looks like it does not _always_ work for
> 60Hz either.
> 
> Should I remove it from patchwork as well?
> 
> As I have the webcam and can perform actual tests I'll coordinate with
> Fabian to have more details about why light frequency filter is not
> working for him with the current code, it works fine for me at 640x480,
> even if I can see that its effect is weaker at 320x240.

I wonder how it could work. Look at the actual code:

	val = val ? 0x9e : 0x00;
	if (sd->sensor == SENSOR_OV767x) {
		sccb_reg_write(gspca_dev, 0x2a, 0x00);
		if (val)
			val = 0x9d;	/* insert dummy to 25fps for 50Hz */
	}
	sccb_reg_write(gspca_dev, 0x2b, val);

According to the ov7720/ov7221 documentation, the register 2b is:

	2B EXHCL 00 RW Dummy Pixel Insert LSB
	               8 LSB for dummy pixel insert in horizontal direction

How could it act on the light frequency filter?

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